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PubMed1983

Peripheral nervous system myelin and Schwann cell glycoproteins: identification by lectin binding and partial purification of a peripheral nervous system myelin-specific 170,000 molecular weight glycoprotein.

Radioiodinated lectins were used to detect glycoproteins of peripheral nervous system (PNS) myelin (rat, human, bovine) and cultured rat Schwann cells. Proteins were resolved by sodium dodecyl sulfate-polyacrylamide slab gel electrophoresis and transferred to nitrocellulose filters. The filters were overlaid with radioiodinated lectins of known saccharide affinities. These included concanavalin A, Helix pomatia, Limulus polyphemus, Maclura pomifera, peanut, soybean, Ulex europaeus, and wheat germ agglutinins. Inclusion of the appropriate monosaccharide in the overlay solution (0.2 M) inhibited lectin binding to the nitrocellulose-fixed proteins. Fluorography permitted identification of 26 myelin glycoproteins and many more in Schwann cells. All lectins labeled a band present in myelin, but not Schwann cells, corresponding to the major PNS myelin protein, P0. Our attention focused on a high-molecular-weight myelin glycoprotein [apparent molecular weight (Mr) 170,000], which appeared abundant by Coomassie Blue staining and which was heavily labeled by all lectins except concanavalin A. A protein with approximately this Mr and lectin-binding pattern was present in human and bovine PNS myelin as well, but not detected in rat Schwann cells, CNS myelin, liver and fibroblast homogenates, or cultured bovine oligodendroglia. Hence this 170,000 Mr glycoprotein is apparently unique to PNS myelin.

Animals↗
PubMed1985

Cultured peripheral nervous system cells support peripheral nerve regeneration through tubes in the absence of distal nerve stump.

Axons of a cut peripheral nerve will grow across a gap (less than or equal to 10 mm in adult rodents) formed when the proximal and distal stumps are placed at opposite ends of an impermeable, inert tube, but will not grow to the end of a blind-ended tube in the absence of the distal stump [Williams et al, 1984]. Work reported here demonstrates that cultured peripheral nervous system (PNS) cells suspended in a collagen matrix will provide an effective milieu that directs and supports axonal regeneration from a severed nerve into a blind-ended tube in the absence of a distal stump. Adult mouse sciatic nerves were cut and the proximal stumps were inserted into close-ended tubes that contained either a collagen matrix containing dissociated cells from embryonic mouse dorsal root ganglia (DRG), a collagen matrix saturated with medium conditioned by cultured DRG cells, or a collagen matrix saturated with fresh medium. In all three cases cellular cables formed that ran the full length of the tubes, but myelinated and unmyelinated axons regenerated the length of the tubes only when cultured cells had been added. The critical factor in influencing axonal regeneration through the length of the tubes was the presence of cultured cells, since collagen alone or collagen saturated with conditioned medium did not support axonal regrowth even though cells had migrated into the chambers from the proximal stumps in all cases. Ordered structure was not a requisite for axonal growth, since the cultures consisted of random arrays of dissociated cells.

Animals↗
PubMed1985

Apolipoprotein E associated with astrocytic glia of the central nervous system and with nonmyelinating glia of the peripheral nervous system.

The plasma protein apolipoprotein (apo) E is an important determinant of lipid transport and metabolism in mammals. In the present study, immunocytochemistry has been used to identify apo E in specific cells of the central and peripheral nervous systems of the rat. Light microscopic examination revealed that all astrocytes, including specialized astrocytic cells (Bergmann glia of the cerebellum, tanycytes of the third ventricle, pituicytes of the neurohypophysis, and Müller cells of the retina), possessed significant concentrations of apo E. In all of the major subdivisions of the central nervous system, the perinuclear region of astrocytic cells, as well as their cell processes that end on basement membranes at either the pial surface or along blood vessels, were found to be rich in apo E. Extracellular apo E was present along many of these same surfaces. The impression that apo E is secreted by astrocytic cells was confirmed by electron microscopic immunocytochemical studies, which demonstrated the presence of apo E in the Golgi apparatus. Apo E was not present in neurons, oligodendroglia, microglia, ependymal cells, and choroidal cells. In the peripheral nervous system, apo E was present within the glia surrounding sensory and motor neurons; satellite cells of the dorsal root ganglia and superior cervical sympathetic ganglion as well as the enteric glia of the intestinal ganglia were reactive. Apo E was also present within the non-myelinating Schwann cells but not within the myelinating Schwann cells of peripheral nerves. These results suggest that apo E has an important, previously unsuspected role in the physiology of nervous tissue.

Animals↗
PubMed2004

The 4C5 antigen is associated with Schwann cell migration during development and regeneration of the rat peripheral nervous system.

The monoclonal antibody 4C5 recognizes a cell surface antigen of the developing central nervous system (CNS) and peripheral nervous system (PNS). In vitro antibody perturbation experiments have shown that the 4C5 antigen is involved in horizontal and vertical migration processes of granule cells during development of the rodent cerebellum. Moreover, results concerning the cellular localization and temporal expression of the 4C5 antigen during development and after injury of the rat sciatic nerve suggested that it may participate in Schwann cell migrations that occur during the above processes. To test this possibility, we examined the effects of our function-blocking antibody on Schwann cell migration in three in vitro bioassays: in tissue cultures from developing sciatic nerve, in dorsal root ganglion cultures on cryostat sections of normal or denervated adult sciatic nerve, and in pure Schwann cell cultures. The results showed that the presence of monoclonal antibody 4C5 in all the above culture systems strongly inhibited Schwann cell migration, indicating that the 4C5 antigen participates in migration processes that take place during development and regeneration of the peripheral nervous system. Moreover, staining of migrating Schwann cells in the presence of monoclonal antibody 4C5 with rhodamine-phalloidin showed that 4C5 antigen activity is associated with actin cytoskeletal organization of these cells, and more specifically with lamellipodia formation.

Animals↗
PubMed1997

Increased apoptosis of T lymphocytes and macrophages in the central and peripheral nervous systems of Lewis rats with experimental autoimmune encephalomyelitis treated with dexamethasone.

Using light and electron microscopic histological and immunocytochemical techniques, we investigated the effects of the glucocorticoid dexamethasone on T cell and macrophage apoptosis in the central nervous system (CNS) and peripheral nervous system (PNS) of Lewis rats with acute experimental autoimmune encephalomyelitis (EAE) induced with myelin basic protein (MBP). A single subcutaneous injection of dexamethasone markedly augmented T cell and macrophage apoptosis in the CNS and PNS and microglial apoptosis in the CNS within 6 hours (h). Pre-embedding immunolabeling revealed that dexamethasone increased the number of apoptotic CD5+ cells (T cells or activated B cells), alphabeta T cells, and CD11b+ cells (macrophages/microglia) in the meninges, perivascular spaces, and CNS parenchyma. The induction of increased apoptosis was dose-dependent. Daily dexamethasone treatment suppressed the neurological signs of EAE. However, the daily injection of a dose of dexamethasone (0.25 mg/kg), which, after a single dose, did not induce increased apoptosis in the CNS or PNS, was as effective in inhibiting the neurological signs of EAE as the high dose (4 mg/kg), which induced a marked increase in apoptosis. This indicates that the beneficial clinical effect of glucocorticoid therapy in EAE does not depend on the induction of increased apoptosis. The daily administration of dexamethasone for 5 days induced a relapse that commenced 5 days after cessation of treatment, with the severity of the relapse tending to increase with dexamethasone dosage.

Animals↗
PubMed1990

Neoplasms of the peripheral nervous system.

Neoplasms of the peripheral nervous system arise from the cellular sheath surrounding the nerve trunks, that is, the pluripotential Schwann cells and related cells, and rarely affect the feet. When present, they are most frequently associated with the autosomal dominantly inherited neurofibromatosis 1. This condition has been related to chromosome 17, and it appears, from in vitro experiments, to involve defects in tyrosine metabolism. Hence, the most common neoplasm is the neurofibroma. Distinct criteria have been established for a diagnosis of neurofibromatosis 1, so that a single pedal neurofibroma may not represent this complex. However, if the complex is present, it is necessary to consider the possibility of malignant transformation to a neurofibrosarcoma. Although malignant peripheral nerve neoplasms are extremely rare in the feet, they may arise in the context of neurofibromatosis 1, or independently. Other benign or malignant schwannomas may (rarely) also arise in the feet. Surgical excision of benign lesions, according to established standards for tumor surgery, is usually curative, but a detailed personal and familial history, along with adjunctive radiologic procedures and biopsy, is necessary to determine the nature of the lesion. Since (endocrine and) other abnormalities may complicate neurofibromatosis 1, surgical procedures must not be undertaken until the patient has been medically cleared and is carefully monitored. A high mortality rate is associated with malignant peripheral neurogenic tumors, especially those arising in the context of neurofibromatosis 1. It should be recalled that neurologic manifestations in the foot may represent non-neoplastic conditions as well as peripheral nerve tumors (or other tumors involving those nerves) that are proximal to the foot and ankle area.

Adult↗
PubMed1983

[Structure of diseases of the peripheral nervous system].

The structure of peripheral nervous system diseases is reviewed by analyzing 941 in- and outpatient case histories. Of this number, 57.34% of the patients had radicular syndromes, 16.17%, acute injuries of nerves and plexuses, and 22.66%, tunnel and other compression syndromes. Cases of polyneuropathy and other disorders accounted for only 3.83%. A total of 21.46 cases with nontraumatic mechanical damage to nerves are analyzed in detail. In 87.88%, these syndromes involved upper and in 12.12% lower extremities. Syndromes of the carpal canal (43.01%), ulnar canal (14.72%), cervical neurovascular compression (12.95%), and tarsal canal (5.08%) occurred most frequently. A wide variety of other syndromes made up only 24.24% of all compression syndromes.

Estonia↗
PubMed1987

[Characteristics of work-loss in diseases of the peripheral nervous system].

Diseases of the peripheral nervous system (PNS) rank fourth among all causes of temporal loss of working ability and first in the structure of neurological morbidity causing temporal disability. Statistical service based on the principles of the International Classification of Diseases, Injuries and Causes of Death does not provide the neurologic service with data about loss of the working time due to PNS diseases. In the comprehensive work on the improvement of neurologic care of patients with PNS diseases conducted in Byelorussia an important place has been recently given to the systematic monitoring of the temporal disability rate which decreased by 28.3% over a period of 3 years (1983-1985).

Delivery of Health Care↗
PubMed2000

The proneural gene amos promotes multiple dendritic neuron formation in the Drosophila peripheral nervous system.

In the Drosophila peripheral nervous system, proneural genes direct the formation of different types of sensory organs. Here, we show that amos is a novel proneural gene that promotes multiple dendritic (MD) neuron formation. amos encodes a basic-helix-loop-helix (bHLH) protein of the Atonal family. During embryonic development, amos is expressed in patches of ectodermal cells, and the expression is quickly restricted to sensory organ precursors. Loss of amos function eliminates MD neurons that remain in ASC;atonal mutants. Misexpression of amos generates ectopic MD and other types of neurons. Amos interacts with the ubiquitously expressed Daughter-less protein in vivo and in vitro. Our final misexpression experiments suggest that a domain located outside the DNA-binding domain of Amos determines the MD neuronal specificity.

Animals↗
PubMed1997

Patterning of the adult peripheral nervous system of Drosophila.

The peripheral nervous system (PNS) of the adult Drosophila melanogaster comprises over one thousand sensory organs (bristles and other types of sensilla) displayed in stereotyped positions of the epidermis. This two-dimensional pattern of sensory organs is generated by the emergence of the sensillum mother cells at specific positions of the imaginal discs, the precursors of the adult epidermis. These positions are largely specified by the interplay of three sets of genes: the proneural genes, their antagonists, and the neurogenic genes. The proneural genes confer upon cells the ability to become neural precursors. Among them, achaete and scute, two genes that encode transcriptional activators of the basic region-helix-loop-helix (bHLH) family, are most important for generating the adult PNS. Their expression is restricted to groups of cells, the proneural clusters, which appear at specific positions of the imaginal discs. Sensory organ precursor cells are born within these clusters. The known proneural antagonists either titrate these proteins by forming inactive complexes (extramacrochaetae) or repress achaete/scute expression at specific sites (i.e., hairy). In both cases, they refine sensory organ positioning by reducing the number of cells competent to become sensory organs. The neurogenic genes mediate cell-cell interactions that prevent most competent cells of a proneural cluster from becoming sensory organ mother cells. Depending on the size and shape of the proneural clusters and on their overlaps with regions of maxima or minima of expression of antagonists, sensory organs are generated either as single elements at unique positions, or as linear arrays containing many elements, or as characteristically shaped, two-dimensional arrangements covering specific regions of the fly's body.

Animals↗
PubMed2005

Metastases to the peripheral nervous system.

Cancer metastasis can affect any part of the nervous system. When the peripheral nervous system is involved, the usual targets are cranial nerves, nerve roots and plexi. However, peripheral nerves and muscles can also be affected by compression or infiltration of neoplastic cells. This review focuses in the diagnosis and treatment of metastatic complications of cancer involving plexi, peripheral nerves and muscles.

Humans↗